Đáp án:
bài 1 :
a) 1/6 + 7/3 - 1/2 b) -8/15 + 13/30 - 5/12
= 1/6 + 14/6-3/6 = -32/60 +26/60 - 25/60
= 12/6 = 2/1 =2 = -31/60
c) -3/8 . 2/5 + -3/8 . 14/5
= -3/8 . ( 2/5 + 14/5 )
= -3/8 . 16/5
= -15/128
d) 3/2 . 7/2 + ( -5/6 + 1/10 ) : 11/30
= 21/4 + ( -50/60 + 6/60 ) : 11//30
= 21/4 + 11/15 : 11/30
= 21/4 + 11/15 . 30/11
= 21/4 + 2/1 = 21/4 + 8/4 = 29/4